This invention relates generally to latches, and more particularly latch mechanisms transmitting actuating movement to strike bolts.
Devices heretofore available for the purpose described herein embody inherent undesirable features which not only present potential sources of trouble, but also make them more difficult to install and maintain in good operating condition.
For example, in one known embodiment, the casing structure and strike plate are permanently connected, and the strike plate also functions as a faceplate. In such a construction, the faceplate portion cannot be varied to meet different aesthetic decorative effects.
In different localities, it is desirable to change the electric actuating coil of the device, for example, to operate under different voltages, or to replace a coil which has failed. In the conventional device noted above, the coil is mounted within the housing or casing of the device, which renders its accessibility difficult.
The device of U.S. Pat. No. 3,638,984 constitutes one solution to the above problem; however, in certain applications there is need for a substantially increased mechanical advantage of motion transmission between the electrical actuator and the strike bolt, within a highly compact assembly; also there is need for an improved, highly compact, basic mechanism adaptable to blocking retraction of a strike bolt, either by operation of a solenoid acting upon a blocking element, or by operation of a torsion spring acting upon the blocking element, thereby facilitating production of essentially the same basic mechanism for operation in either of such modes.